The present invention is about a positive-displacement reciprocating compressor, suitable for being used in several applications, like for instance to feed spray guns or in tools of compressed air type, for performing blowing operations in machine shops, or other.
It is known that, to produce the compressed air required for performing operations like the painting of industrial products, for instance automobiles or earthmovers, positive-displacement reciprocating compressors are used, which compress variable air flow rates according to the use requirements.
Said compressors generally comprise a piston, or plunger, which, sliding inside a cylinder, compresses the air sucked from the surrounding environment for supplying it to one or more users at a higher pressure.
The piston performs a reciprocating motion inside the cylinder, according to an operation known for the man skilled in the art.
The movement of the piston is obtained through the so called “oscillating piston” mechanism, it too well known for the persons skilled in the art.
The compressed air produced by the compressor is usually stored in a tank for a subsequent utilization.
However, said compressors have some acknowledged inconveniences.
A first inconvenience is due to the fact that, for the intrinsic features of the “oscillating piston” mechanism, the sealing elements or gaskets coupled with said piston undergo stresses that cause a rather considerable wear degree.
This is due to the continuous irregular oscillation of the piston inside the cylinder, which causes an excessive rubbing of the sealing elements against the cylinder inner walls.
Consequently, maintenance or replacement interventions of the sealing elements are required, with the inevitable material and labour costs this involves.
A second inconvenience is due to the fact that, in order to limit the sealing elements wear, the oscillating piston performs an incomplete stroke inside the cylinder.
As a result, there is a lower production of compressed air, and thus lower efficiencies of the compressor with respect to the possible and expected ones.
A further inconvenience of the aforementioned compressors is due to their high constructional complexity.
Another inconvenience is due to the fact that the compressors according to the prior art described hereinbefore are not able to produce a continuous flow of compressed air when operated.
As is well known, this fact leads to undesired operative conditions, in which the compressed air exits intermittently from the compressor and the operation that it has to perform is performed in an imprecise and inadequate way.
To overcome the latter inconvenience, the compressors of known type are provided with a storage tank in which the compressed air is stored before being used.
The capacity of the tanks nowadays available on the market ranges from 25 to about 5000 liters, and thus there are several types of use, varying from hobbies to industrial utilization.
Only after the complete loading of these tanks, the compressed air is stably and readily available to the users.
The compressed air flow supplied by the compressor is thus made continuous and the optimal operative conditions to correctly perform the workings are obtained in use.
However, this solution of known type too has a first inconvenience due to the fact that the tanks considerably increase the overall dimensions of the compressors, this aspect being of particular relevance in those applications in which practical and easy manoeuvrability and handling of the compressor are required.
Another inconvenience is due to the danger related to the presence of the tank.
A further inconvenience is due to the need to produce more compressed air than that actually required at every use.
Indeed, when the compressor is stopped, it is required to refill the tank with its nominal flow rate to make efficient its subsequent use.
This involves an additional series of operations and an energy loss which could be avoided.
Not the least inconvenience is due to the fact that the arrangement of the tank further complicates the constructional shape of the compressors.